Analog meters of the type having a circular dial including a scale on the periphery of the dial and a rotatable pointer located at the center of the dial are widely used throughout the world. Such meters are fairly inexpensive to manufacture and provide clear and accurate indication of the measured information. Since this type of analog meter presents easy to read information for a viewer, these meters become the first place the viewer checks during routine scans of all the instruments. In performing routine checks of all the instruments, it is important to present in an effective manner to the viewer situations in which possible errors may be occurring which require immediate attention by the viewer. For example, if the oil pressure in an engine dropped to zero, the viewer requires the information as soon as possible in order to react quickly to the pending engine failure that may occur.
Some analog meters provide LEDs located behind the surface of the dial at the pointer's pivot position for illuminating the pointer, which is usually composed of a translucent plastic material, through a prism located at one end of the pointer. These LEDs are connected to the signal sent to the analog meter for allowing the LED to react when the signal reaches a level that requires that an error or emergency signal be sent to the viewer. The LEDs react by flashing, thereby presenting a pointer that appears to be blinking with the color light of the LED. This is an effective tool for presenting error conditions to a viewer during low-light or nighttime situations, when the light illuminated by the LED within the pointer is relatively easy for the viewer to see. However, during times when high intensity light is shining on the meter or a glare exists around the meter, usually due to bright sunlight, a viewer may have a difficult time seeing the LED generated light illuminated within the pointer, whether steady or flashing. The LED generated light is "lost" in the background light. Therefore, in these situations, errors or emergencies indicated by the signal information supplied to the meter can go unnoticed for an unduly long period of time. It is important to note that time is a critical element when many errors or emergencies occur.
The present invention is directed to overcoming the foregoing and other disadvantages. More specifically, the present invention is directed to providing an apparatus for positively displaying meter signal information in both normal and abnormal detectable parameter conditions, and at both low and high ambient lighting conditions.